thompson



L t e e h m e e h S 4 N O S P M O H T G WM 0 I VALVE MECHANISM FOR-ENGINES. No. 605,030.

Patented May] 31,1898.

0. W. THO MPS N. VALVE MECHANISM FOR. ENGINES.

4 SheetsSheet 2.

i (ND Model.)

No. 605,030. Patehted May 31,1898.

uma/70R.

- W/m [ww- I v (No Model.)

4 sheets -sheet 3'.

0 W THOMPSON VALVE MECHANISM FOR ENGINES. ,030, BatentedMay 31,1898,,

F MM/WOR ATTOR/VE'YJ- w/rmsaae'o 4 She tsSheet (No Model) a v 0w; THOMPSON. I

VALVE MECHANISM FOR ENGINES.

N 005,030v Patntgd May 31, 1890.

ms ATTORM! w l. I j To all whom, it may concern:

1 STATES,

PATENT OFFICE.

ooUR'rENAY ILLIAM TIIOhIPSQN, on Lon-Don, ENGLA D.

VALVE MECHANISMFOR ENGINES.

. SPECIFICATION forming part of Letters'Patent No. 605,030, dated la er, 1898 Application aerosol) 24,1896. sent: No. 509,936.

Be it known that I, CO'URTENAY WILLIAM THOMPSON, mining-engineer, a subject of the Queen ofGreat Britain, and a resident of 30 College road, Bromley, London, in the county "of Kent, England, tempoifarily residing at "Naymouth street, Adelaide, in the Pirovince of 'South'" Australia, have invented new and useful Improvements in Valves and Valve Mechanisms for Engines Operated by Steam or other Expansible Motive Agent, (for which I have obtained Letters Patcntin Great Britain,No. 8,049, dated April 16, 18%,) of which the following is a specification. r

The principal object of my invention is to provide valves whereby-the exhaust or cushioning conditions of the motive fluid (which I will hereinafter. refer to as steam )-can be cont-rolled or regulated-independently by providing a cushioning-space between the compression from be suitably for themegulation of/steam out off main and the cut-off valves, whichreceives alternately, and to provide valve mechanisms -to increase the eiiiciency ofstheexhaust con- "ditions in relation to the dis-iribution of steam in the engines and 'to suit I he varying conditions of reversing or non-reversing engines.

Figure I is, a sectional/view illustrating a valve mechanism acoorging to'my invention. Fig. 2 is a sectional vietion of valve mechanism with linkage-operating mechanism. Fig. 3

isa view'similar to T Fig. '2 of another modification.Eig. 4=.is;a

sectional; view of another modification of 1' .valve mechai isn n Fig ;l5 is a sectional view of the fiatvalve mechanism equivalent to that .shown in'fFigw i, -Figs, I6, bf and 8 are sections showing other modificationsof valve n'ie'chanism. Figs. 7 and 7 are diagrammatic views of a reversing mechanism; andFigs. .9, 10, 11, and '12 show different forms of linkage for controlling the valves, as hereinafter ex plained. 1 Q

In some instances I provide a. separate ex haust-valve tobeused as an auxiliary to and i toh valv e controlled independently of the main stea and enhaustg. For instance, in Fig. 1

of the accompanying-diagrams the valve B represents the main valve (for simplicity and th endsof the cylinder" of a slight medifica hen snchmain valve operates for both momma.) Patented ihEu lkiidLjdllB,1896mm 8,049;

steam typelcohtrolling both steam and exhaust in the ordinary way, Whereas. the valve A'only controls the exhaust, butgis shown with no inside lap, so as to be open to the cushioning. The steam may also be admitted to such a valve, as A, when the greater power (is required, the steanpchest being indicated by X, steam-ports to cylinders by s, and ex haust by '7' in all the figures.

I will describe the nature of my inventionand the manner in which'it maybcperfoixned by reference to the examples illustrated in the accompanying diagrams, but I Wish it to be understood that these are only e3 mples in elucidation of'my invention and t; atIdo not limit myself to the particular devices shown.

"Fig. 1 has. already been described, but in connection with" the" opera-ti u g mechanism the valve B will always-operate best with more angular lead and less travel than those of the Valve A. I 1 p g Any of the valves described in this specification may operate with any suitable gears.

For instance, thevalve A, Fig. 5, may he opera'ted by any suitable main valve-gear and the valve B, Fig. 5, by any suitable expansiongear,, and any mechanisni'herein described may operate with any suitable valve systemsuch, for instance, as any ordinary and suit able expansion-valve system;

The valve system shown in Fig. 2 is practically the same as that in Fig. 1, but the mechanism is such that the spindles cannot pass direetly to the centers of the valve-pistons. This valve system is only suitable to be used under the conditions accordingto'my invention for forward running, but iii-is shown in connection with reversing mechanism, such as a marine engine, where the c'conomyin reverse running is of little or no importance and where this eanbe sacrificed forthe sake of economy in forwardrunning.

- I provide twoblocksin theonecontrolling-' link, which give the valveB more lead and less travel than thoseof the valve A. The reverse, however, is the case when the engine is-reversed.

link, for example, (or its equivalent,) may be used in this manner for non-reversing en'- ginesl When such a' mechanism with two blocks or valve-pins in the one link is used The forward hall. of a reversing IQO one valve being for steam admission 20 valve B opens too early.

5 used.

50 adding a Sligl|tly-Qrcnior amount et' outsn 6oin}; is given back in full.

'65 plates and ports of the valve l with such an engine as a l ewntiitivc where forward and reverse worhin; are important,- then the ports and valve-tamer ot' tin;- v lve A must be the same as those in ii -lve i, the it l'orward and the other in reverse rnnnimralternatively. Steam is then only admitted to one valve at one time-viz., the one ha ing the most lead and the it .t travel--hut whenv "10 great quantity of steam is required then such ducing equivalent et't'eets on the val The principal duty of the valve A is to con trol the exhaust, but it also rog'nla t moment for admitting steam when it is news sary, as the steam controlling: or exprnision This valve and gear maybe used, for example, formarinc engines;

but the most useful marine-engine valve thatshown in Fig. 7', operated hysuch a g ar as that shown in l ig. The steam-admission valve B may he or" that piston or other form. In Fig. tlikewise the valve ll must have more lead and less travel than those of the valve A, whereas unlike the valve ii in Fig. 3 the lap at the valve I in Fig. lis So 0 proportioned that it regulates both the opr-ning and closiuu to steam. Both the valves A and l; are shown in the central positional their travel. In thiscase t he valve A. may have no inside'lap at all, an! tf'onsoqut-ntlyal the 5 clearance-space may he in cnnnnzmication 40 intensity of the cushimted or haul; pressure under the varying conditiozr: ot' the cunotl. Thisarrangementisznostnsctul in compound engines, where the pressure at the exhaust varies in proportion to the amount, of steam This heneticial et't'cct is further increased and rendered a pplieahle to both simple and compound engines, as shown in the valve-faces of the valve it in l ig'. t, hy.--'liuhtl v cutting out the inside or steam lap and by v i it. orexhaust lap relativelytothecylin'ler-ptn'is, so as to have the clearance or cushioning space lillcdhystt-am just nrevioustooxhaust and so as to transfer the steam under such ure to the other end of thecyllndcr. 'lhe cushioningspacc is never open to exhaust, but is always open to the steam end ot the cylinder, that while it prevents any excessive cushioning all the worl; done in cushionlhis et't'ect is prod r-cd by varying the movement of the haust or cushioning valve, as w -ll as that of the steam-valve, and in (:ontradistint'lion to the ordinary expansion valve -;t-ar. 'lh may he don-- bled or treblcd or further multiplied.

ft ho valve l; niayl 3 given "precisely the same movement as that given to the valve A when the clearance or cushioning space will require to be larger than if the valve B had more lead and less travel than those of the valve it, as in the former case the compression will always be greater than in the latter case.

With. such a valve as-A in Fig. 4, for example, when there is little or no steam lap, the same size of steam-opening can be e1- fcctcd with halt the travel that is necessary with an tudinary valve. The exhaust-ports may then he doubled, while the steam-port is only single, without increasing the weightof the valve when the travel is halved and retaining the diameter of the valve equally full port-openings are obtained with half the travel of the heavy valve, whereas the small valve l3 requires very little moving, and simultaneously the full advantage of the suitably proportioned cushioning-space is provided for the variable amounts of steam consumed.

For very high speeds and powers the steam may he admitted directly to the cushioningspace between the two pistons of the valveA no arrangement shown in Fig. 4 has another great advantage, that it entirely pro-' vides against the trouble which exists with pi-ton-valves of so closing the ports as to inclose condensed water and not permitting it to escape and the consequent danger 'ofi knocking out the cylinder end. By the arxanicment Fig. -t free access is provided from the cylinder to the cushioning-space and it necessary through the expansion valve, which rises r adily ell its seat to any access of pressure. The cushioningspace can besides be readily drained by a relief or other valve placed at its lowest point. In this and other valve systems herein the steam-admission valve B may be operated hya shaft-governor. If the engine he reversed, then steam may be admitted directly into the steam or cushioning space of the valve A and the nnreversed valve l3 rendered inoperative.

The valve arrangement shown in Fig. 5'is the flat valve equivalent of that shown in l ig. :land includes slide-valves whether of llat piston, oscillating, or other kind.

in Fig. 5 the valves A and It are cqhivalent to the valves A and I5, respectively, in Fig. 1. X is the steam-chest, and Y is the clearance or cushioning space. When a cushioningspaee provided in the manner shown in Figs. #1 and there can be no knocking ofor inclosin r of condensed water in the cylinder, and the bulk of the cushioning-space should be low down with a rclict' or other valve at the lowest point.

The eomhi.nuioinvalve A ll shown in Fig. i gives the some rtsn ts as those given hythe 'arraugemerns l igs. 4 and 5, when the slide thence into the valve-chest as those of the valve B of Figs. etand 5. Thus in Fig. '6 the passages in the valve between the faces A and B communicate with the cushioning-space Y and with the two ends of the cylinder, whereas the faces B 13 control the steam distribution in the same manner, the faces A A controlling the exhaust and cushioning in the particular manner according to this'in'vention. The valves A B may be fitted or balanced in the steamchest X in any convenient manner, and thisv valve may be very beneficial when operated by a shaft-governor eccentric, or generally when there is only one slide both for variable expansion and exhaust.

' The valve arrangement in Fig. 6 may be modified by providing a port in the face Z and an expansion-valve to operate 'on the back of such port, and, further, by providing more steam lap at B B. The auxiliary expansion-- valve will be operated so as to always out off the steam early, (see Fig. 8 for a suitable n'ature of mechanism for this,') whereas the modified faces B B would only' operate for steam admission and cutoff for the latter points of cut-oft. This modified form will be most useful with a reversing mechanism in which both valves can be controlled by one lever. (See Fig. 9.) This modified form, Fig. 6, is best seen'in' Fig. 6. The lap is increased at the faces'li BL The expansion-valve Z operates 'the port Z on the back of the plate Z. In

Fig. 6, X is an auxiliary steam-chest. This,

cut-oil of steam, whereas the valve A B op crates only for late cut-oil of steam. Consequently the valve A 13 never has its travel so much reduced and never effects so heavy cushioning as does an ordinary simple valve. Equivalent arrangements to those shown in Figs. 6 and ('3 are, for example, as follows: The valve in Fig. 6- rnay carry a partot the cushioning-space, moving as a part of itself, and, further, a steam-admissioh valve may operate in connection with this cushioningspace--as, for example, it does in Fig. 0. As illustrated in Figs. 5, 6, 6", 7, and 9, for instance, the various slides maybe interchanged and combined in any suitable manner that their particular properties suggest. This cushioning-space, it will beseen, is the space between the main valve and the cut-oil? valve, and it receives compression from both ends of the cylinder alternately, and through this same space the two ends of-the cylinder alternately aoinmunicate with one another. This space may be regulated in capacity to suit the press-upset the steam in use, so that the pressure of the coi'nprcssion at the end of each stroke-of the piston may he raised unvarying conditions of cut-off as near as possible to that of the live steam in the steanr chest. Again, according to myinvention this space may be or any shape, with the object in some instances of placing the two valves at diii'erent parts of the cylinder. For instance,

ment is transmitted to the upper end F.

the main valve may be on the side of the cylinder and thecut-ofi valve on t.het0p,-when ing to this invention, is to regulate the steam as the admission valve, andto the valve whose principal duty, according to this inven tion, isto regulate'the exhaust or cushioning as the exhaust or cushioning valve.

1 will particularly describe Fi 7, for example, in connection with Fig. 6. Fig. 7 is an elevation, and Fig. 7 aside view. The rockingshaft 0 supports an ordinary reversing-link, at or about the center of the latter, and obtains a-rockingmovement from it. This movement is transmitted to the shaft E. The ordinary valve movement is transmitted by the block to the lower end of the lever of the rocking shaft D, through which the move- The rocking'arm E B A reccives one movement from its rocking shaft E and another movement from an arm connected by suitable attachment to the rocking arm F. .Thus the rocking arm B A has movements equal to .-may operate the ad mission-valve, and the pin A may operate the exhaust or cushioning valve. The single controlling-lever L controls both of the pins A and B so that the pin 13 will always have an earlier cut-off movement than has the pin A, and A may therefore 01)- erat the valves Pi" and A B, respectively, in Fig. 1

in Fl 8 the valve A is the exhaust or cushioning valve. 13 is the steam-admission valve, and'll is an auxiliary steam admission valve operating on the hack of the anchorplate C The valve B also controls the exhaust, effecting an early opening to exhaust when desired, but it will always close the ex-' haust before the valve A will close it. If the steam lap of the valve B be so increased that the valve B will not open to steam at all, then this valve may be used with the'gear shown in Fig. 2.

equally well for forward or reverse Workingv and is a very suitable combination for a locomotive. From the. foregoing it will be seenthat in the modified form of Fig. 8 tho valve:

One block will be attached to the valve A and the other blockwill be attached As new it is the first of.

ICC

A and the valve B B may each be alternately eccentric It on either side of the center.

I is the shaft-governor eccentric.

steam admission or exhaust valves, respectively, and accordingas the engine is run ning forward or reverse,

' In Fig. it the main or exhaust or eushiow ing valve attached to the block A is controlled by governor or otherwise in the same variable link as is the expansion or admission valve attached to the other block I. Thisisanon-reversinggear. The eccentric-Ii is attached to the link atand the eec cntric I is attached to the link at D. D is the early cut-off, and (1 is the lat e cut-oil, end of the link. The early cut-ot't' eccentric I is set opposite to the crank, and half its travel is about equal to the lead of the late cut-ot't This gear may be used with the arrangement Figs. 4, S, and others. The block 3 has always more lead and less travel than has the block A In the arrangement Fig. I the varying lead and travel properties are obtained, for example, from the one block in the reversing-link. There are two pins in this block connected to two valve-rods. The two valve rods are supported by reason of the one block being supported by the rod (7'. This gear is suitable, for example, for a locomotive, and the movements for the valves may be transmitted suitably by the rocking shafts. The pins A and ,liare alternately (and as the englue is reversed to and fro) applicablchw an admission-valve and an exhaust or cushioning valve, respectively, and they mayoperate, for example, with the valves shown in Itigs. 2 and 8. There may be three pins in the one block or three blocks in the one link, and, for example, the two outside ones may be admission-valves alternately.

I'Iu the arrangement Fig. 11 the varying lead and travel properties are (.bained, for example, under the followingeord tions: A is a shaft-governor eccentric, and is operated with the variable movement, the exhaust or cushioning valve rod Iiflwhile the movementfor the zulmission-valve rod A is obtained at sucli an angle that A operates always with more lead than does II". This et't'ect is produced by attaching A to' a point in the e centric-strap d'itl'erent from that ot' ll". The rods IVA operate through the medium of the rocking shaft It.

In the arrangement l ig. t2 the varying lead and travel properties are obt-ainel, for example, under the following conditions: A" l is an ere centric set opposite to the crank, and its halt travel is about equal to the lead of A on either side of the center. The eccentric A is shown as operating the admission-valve di reetl v, and it is attached to the link A B at A Ihc eccentric I3 is attached to this linl:v at- I In varying both the admission 7 id exhaust or cushioning valves A has alnays more lead and less travel than has I It is understood that figures of the drawings only illustrate some modifications of the main principle involved, as the main and cut-oft valves may be of any form or design which will produce the etteets of the invention as described, which requires, with the arrangement of val re-faces and port-faces described, that there shall be a cushioning-space between the main and cut-off faces of the two valves in the valve system 'in order to produce the effects described, and the two valves need not be placed relatively to each other, as shown in Figs. 4: and 5, but may be placed in some instances the one on the top of the cylinder, say, and the other on the side or otherwise, provided that they will produce the et'tect provided for and described in the specification.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is- 1. In fluid-operated engines, the combination of a cylinder, with the main valve or alves, and the cut-oft valve, having a cushioningspaee located between the main and cut-ol't valve-faces and adapted to receive compression altc, rnately l'rou' both ends of the cylinder, and mechanism to. operating said valves, whereby the exhaust and cushioning conditions are controlled independently of the control of the variable expansion, substantially as described.

2. In tluidopcrated engines, the combination of a cylinder, with the main valve or valves, and the cut-oil. valve, having a cuslr ioningspace located between the faces of the main and cut-oil" valves and adapted to receive compression alternately from both ends ot the cylinder and to alternately place the ends of the cylinder in communication, and meehan ism for operatingsaid valves,whcreby the exhaust and cushioning conditions are controlled independently of the control of the variable expansion, substantially as de- Scrlbtitl.

In testimony that I claim the foregoing as my invention I have signed my name, in the plOHUi ICO of two witnesses, this 31st day of August, 18th}.

(.Ot 'lt'lliNAl' WILLIAM THOMPSON.

Witnesses:

tiuxumcs NICHOLAS COLLISON, An'rut'u (tour: CoLmsoN.

IIO 

